What is Hey Kiddo?
1.
A phrase, used occasionally when greeting, someone within a close proximity to your own age (1 day-1 year).
Used more frequently by a non-relative when greeting a (friend's possibly) child.
Katie: (to Jeff) "Hey Kiddo"
Jeff: "Oh shut the hell up I'm only 3 weeks younger than you"
Katie: "Still fucking younger kiddo"
or
Old guy: "Hey Kiddo" (some form of annoying touching i.e. cheek pinch)
Teenager: "WTF?!?!"
See 
Random Words:
1. 
The fat rolls on the back of a fat persons neck.
Man the fat dude has half a dozen neck fritters.
See rolls, fat rolls..